docs: remove curl|sh one-liner in favor of conductor CLI

The conductor_server.sh one-liner downloaded a 606 MB JAR to the
current directory with no progress indicator and ran in the foreground.
Replace it with the `conductor server start` CLI approach, which handles
download location, caching, and UX correctly.

Fixes conductor-oss/getting-started#47

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: nthmost-orkes

README.md

@@ -54,11 +54,15 @@ docker run -p 8080:8080 conductoross/conductor:latest
 ```
 The UI will be available at `http://localhost:8080` and the API at `http://localhost:8080/api`
 
-**MacOS / Linux (one-liner):** (If you don't want to use docker, you can install and run the binary directly)
+**Conductor CLI** (macOS / Linux, if you don't want to use Docker)
 ```shell
-curl -sSL https://raw.githubusercontent.com/conductor-oss/conductor/main/conductor_server.sh | sh
-```
+# Installs conductor cli
+npm install -g @conductor-oss/conductor-cli
 
+# Start the open source conductor server
+conductor server start
+# see conductor server --help for all the available commands
+```
 
 ## Install the SDK